About printf() out on UART5 of STM32F3DISCOVERY Board

[Kye-Hyun Park]

I'm testing printf() out on USART1 and UART5 of STM32F3DISCOVERY Board.

USART1 tx (PC4) <-> RS232C converter

UART5 Tx (PC12) <-> RS232C converter

printf() out on USART1 is working normally. but, printf() out on UART5 is not working.

Could you please check my code?

Best regards,

[Code for USART1 Tx Configuration ]

// Retargets the C library printf function to the UART
#ifdef __GNUC__
 #define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
 #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif // __GNUC__
 
PUTCHAR_PROTOTYPE
{
 // Place your implementation of fputc here
 // e.g. write a character to the USART
 USART_SendData(USART1, (uint8_t) ch);
 
 // Loop until transmit data register is empty
 while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET){}
 
 return ch;
}
 
void ConfigureUSART1(void)
{
 // Enable GPIO clock
 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC, ENABLE);
 RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
 
 GPIO_InitTypeDef GPIO_InitStructure;
 
 // Configure USART1 Tx as alternate function push-pull
 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
 GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
 GPIO_Init(GPIOC, &GPIO_InitStructure);
 
 // Connect PC4 to USART1 Tx
 GPIO_PinAFConfig(GPIOC, GPIO_PinSource4, GPIO_AF_7);
 
 // Configure USART
 USART_InitTypeDef USART_InitStructure;
 
 USART_InitStructure.USART_BaudRate = 19200;
 USART_InitStructure.USART_WordLength = USART_WordLength_8b;
 USART_InitStructure.USART_StopBits = USART_StopBits_1;
 USART_InitStructure.USART_Parity = USART_Parity_No;
 USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
 USART_InitStructure.USART_Mode = USART_Mode_Tx;
 
 // USART configuration
 USART_Init(USART1, &USART_InitStructure);
 
 // Enable USART
 USART_Cmd(USART1, ENABLE);
}

[Code for UART5 Tx Configuration]

// Retargets the C library printf function to the UART
#ifdef __GNUC__
 #define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
 #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif // __GNUC__
 
PUTCHAR_PROTOTYPE
{
 // Place your implementation of fputc here
 // e.g. write a character to the USART
 USART_SendData(UART5, (uint8_t) ch);
 
 // Loop until transmit data register is empty
 while (USART_GetFlagStatus(UART5, USART_FLAG_TXE) == RESET){}
 
 return ch;
}
 
void Configure(void)
{
 // Enable GPIO clock
 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC, ENABLE);
 RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART5, ENABLE);
 
 GPIO_InitTypeDef GPIO_InitStructure;
 
 // Configure USART5 Tx as alternate function push-pull
 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
 GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
 GPIO_Init(GPIOC, &GPIO_InitStructure);
 
 // Connect PC12 to USART5 Tx
 GPIO_PinAFConfig(GPIOC, GPIO_PinSource12, GPIO_AF_7);
 
 // Configure UART
 USART_InitTypeDef USART_InitStructure;
 
 USART_InitStructure.USART_BaudRate = 19200;
 USART_InitStructure.USART_WordLength = USART_WordLength_8b;
 USART_InitStructure.USART_StopBits = USART_StopBits_1;
 USART_InitStructure.USART_Parity = USART_Parity_No;
 USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
 USART_InitStructure.USART_Mode = USART_Mode_Tx;
 
 // UART configuration
 USART_Init(UART5, &USART_InitStructure);
 
 // Enable UART
 USART_Cmd(UART5, ENABLE);
}

[Tesla DeLorean]

GPIO_PinAFConfig(GPIOC, GPIO_PinSource12, GPIO_AF_5); // PC12 UART5_TX AF5

[Kye-Hyun Park]

I did a mistake for configuration of AF. I just confirmed that printf out on UART5 is working. ​

Thank you for your reply, Clive Two.Zero